Harem Startup : The Demon Billionaire is on Vacation

Chapter 780 – Sovereign of Twin Sins

The shadow receded slowly.

Returning to the darkness at the center of the chamber.

But its voice echoed one last time.

”Use it.”

Lux collapsed forward onto one hand, breathing hard.

Sweat dripped from his hair onto the obsidian floor.

His chest still glowed faintly where the sigils had changed.

The system finalized the message.

[You have been blessed by the Original Sin.]

And the chamber fell silent.

For exactly three seconds.

Then something inside Lux’s body made a crack.

Not metaphorically.

Not spiritually.

An actual, deeply unpleasant crack.

Lux froze on one hand against the obsidian floor.

”...Oh no.”

He didn’t say it out loud.

But his brain said it.

Loudly.

Very loudly.

Another crack followed.

This one traveled up his spine like someone snapping dry branches one vertebra at a time.

Lux’s eyes slowly widened.

’That... doesn’t sound good.’

The pain hadn’t vanished like some heroic transformation moment.

No.

It had simply changed jobs.

Instead of stabbing his chest, it now spread through his entire body like molten iron being poured into bones that were absolutely not designed for that amount of drama.

Lux inhaled sharply.

Then exhaled slowly through his teeth.

’Stay calm.’

’Stay calm.’

’You survived infernal audits.’

’You survived celestial negotiations.’

This was probably...

Another CRACK.

Lux jerked upright instinctively. ”...Okay that one was my ribs.”

Across the chamber, Asmo leaned casually against the invisible barrier, watching with growing interest.

Lux didn’t look at him.

Because if he looked at him he might see that stupid amused face.

And if he saw that face...

He might throw something.

Lux pushed himself upright slowly.

Every joint protested.

His shoulders rolled back involuntarily as something shifted beneath the skin.

His aura flickered again.

Green.

Pink.

But now there was something else in it.

Something darker.

Older.

Lux felt it settle inside his demonic core like a throne being installed in the center of a burning city.

The system flared again.

[WARNING: Structural Evolution Detected]

Lux blinked. ”Oh come on.”

Another wave of pressure rolled through him.

His wings erupted out of his back first.

Not the elegant Greed wings he usually summoned.

These were larger.

Sharper.

Black with veins of crimson light threading through them.

Lux stared over his shoulder.

His tail snapped into existence next.

Longer.

Heavier.

With a spade-shaped tip glowing faintly with Lust energy.

Lux sighed.

’Fantastic.’

Then the horns.

Greed horns had always been sleek.

Refined.

Corporate demon aesthetic.

Now they curved differently.

Longer.

More primal.

One swept back like an infernal crown while the other curved slightly forward.

Lux rubbed his temples.

”Of course the horns changed.”

Because why not.

His body straightened instinctively.

Muscles tightened under his skin as the transformation finished locking into place.

Lux felt it immediately.

Strength.

Not explosive rage strength like Wrath demons.

Not reckless brutality.

This was controlled power.

The kind that moved with precision.

Like a blade instead of a hammer.

The system exploded across his vision with notifications.

[Form Evolution Complete]

[New Demonic Form Acquired]

[Primordial Incubus Sovereign Form]

Lux blinked slowly.

”...That name is excessive.”

The system ignored him.

[Class Evolution Detected]

[Previous Class: Infernal Sovereign]

[New Class: Sovereign of Twin Sins]

Lux paused.

His brain processed that sentence like a CFO reading a suspicious contract.

’Twin Sins. ...That actually sounds terrifying.’

The notifications kept coming.

[New Combat Attributes Unlocked]

[Sovereign Instinct]

[Reaction speed and combat perception drastically increase when facing stronger opponents. Predictive instinct improves under threat.]

[Sin Resonance]

[Greed and Lust amplify each other during battle. Damage increases when Lux successfully controls or overwhelms an enemy.]

Lux blinked slowly again.

’Okay. Those are actually useful.’

But the system wasn’t finished.

Because apparently today was the day Hell decided Lux Vaelthorn needed an entire software update.

[New Ultimate Skill Unlocked]

Lux squinted at the screen.

The skill appeared.

[Kingbreaker]

[Unleashes a violent burst of twin Sin energy that explodes on a chosen enemy. The impact fractures their class authority and crushes their level advantage. For a brief time, the target is stripped of skills and forced to fight with only their base strength.]

Lux stared at the description.

Then read it again.

Then a third time.

His internal monologue slowly restarted.

’...I can tell someone’s class to sit down.’

He blinked.

’That is extremely illegal.’

Across the chamber, the barrier finally dissolved.

Asmo stepped forward casually.

Lux didn’t turn around yet.

Because he was still processing the fact that his ultimate skill basically said ”Your build doesn’t matter anymore.”

Lux slowly rolled his shoulders.

The new wings flexed slightly behind him.

He exhaled.

Long.

Slow.

His body still ached like someone had rebuilt him using volcanic metal and bad intentions.

But underneath the pain...

There was something else.

Power.

Real power.

Not just financial leverage.

Not just political influence.

This was personal.

Direct.

And extremely dangerous.

Lux rubbed his face.

’Fantastic. Now I have to manage this too.’

He straightened his posture instinctively, already slipping back into composed executive mode.

But inside...

His brain was still screaming quietly. ’I came here for a quick heritage check. Now I have a primordial Lust blessing and a class-denying ultimate.’ Lux exhaled again. ’...This meeting went slightly off agenda.’

The chamber behind him had gone quiet again, the oppressive ancestral pressure retreating into whatever ancient abyss it normally slept in. The sigils on the walls dimmed. The air stopped vibrating with whispers.

Which was good.

Because Lux’s brain felt like someone had unplugged it, plugged it back in, and installed three incompatible operating systems.

Behind him, footsteps approached.

Asmo.

Lux didn’t turn immediately. He was still mentally inventorying his body like a man discovering unexpected furniture in his house.

Chest sigils upgraded.

Core restructured.

Primordial blessing.

New class.

Illegal ultimate skill.

Asmo stopped beside him.

”You okay, kid?”

Lux considered the question carefully.

”Kinda.”

Which was technically true.

He wasn’t dead.

That was always a promising start.

Lux flexed his fingers once, feeling the strange new stability inside his core. The Greed engine was still there, humming with familiar cold precision.

Lux exhaled.

”So...” he said slowly.

He gestured vaguely at his own chest.

”I got... this stuff now.”

Asmo raised an eyebrow.

Lux glanced sideways.

”You okay with it?”

For a moment Asmo just stared at him.

Then the Lord of Lust burst out laughing.

Not polite chuckling.

Full-on, chest-shaking laughter.